Problem: $ (-4.2\% \div -7\%) \div -20\% $
Explanation: Convert each percentage into a decimal dividing by $100$ $ (-0.042 \div -0.07) \div -0.2 $ $ = -0.042 \div (-0.07 \times -0.2)$ $ = -0.042 \div 0.014$ ${0}$ ${0}$ ${1}$ ${4}$ ${4}$ ${2}$ ${0}$ $\text{Shift the decimal 3 to the right.}$ ${4}$ $\text{How many times does }14\text{ go into }{4}\text{?}$ ${0}$ ${4}$ $-\vphantom{0}$ ${4}\div14={0}\text{ or }14\times{0} = {0}$ ${2}$ $\text{How many times does }14\text{ go into }{42}\text{?}$ ${3}$ ${4}$ ${2}$ ${0}$ $-\vphantom{0}$ ${42}\div14={3}\text{ or }14\times{3} = {42}$ ${0}$ $\text{How many times does }14\text{ go into }{0}\text{?}$ ${0}$ ${0}$ ${0}$ $-\vphantom{0}$ ${0}\div14={0}\text{ or }14\times{0} = {0}$ A negative number divided by a positive number is a negative number. $-0.042 \div 0.014 = -3$ Convert the decimal into a percentage by multiplying by $100$. $-3 = -300\%$